The ‘keto diet’ is a currently popular high-fat, low-carbohydrate diet; it limits the intake of glucose which results in the production of ketones by the liver and their uptake as an alternative energy source by the brain. It is said to be an effective treatment for intractable epilepsy. In addition, it is being promoted as a so-called alternative medicine (SCAM) for a wide range of conditions, including:

  • weight loss,
  • cognitive and memory enhancement,
  • type II diabetes,
  • cancer,
  • neurological and psychiatric disorders.

Now, it has been reported that the ‘keto diet’ may be linked to higher levels of cholesterol and double the risk of cardiovascular events. In the study, researchers defined a low-carb, high-fat (LCHF) diet as 45% of total daily calories coming from fat and 25% coming from carbohydrates. The study, which has so far not been peer-reviewed, was presented Sunday at the American College of Cardiology’s Annual Scientific Session Together With the World Congress of Cardiology.

“Our study rationale came from the fact that we would see patients in our cardiovascular prevention clinic with severe hypercholesterolemia following this diet,” said Dr. Iulia Iatan from the Healthy Heart Program Prevention Clinic, St. Paul’s Hospital, and University of British Columbia’s Centre for Heart Lung Innovation in Vancouver, Canada, during a presentation at the session. “This led us to wonder about the relationship between these low-carb, high-fat diets, lipid levels, and cardiovascular disease. And so, despite this, there’s limited data on this relationship.”

The researchers compared the diets of 305 people eating an LCHF diet with about 1,200 people eating a standard diet, using health information from the United Kingdom database UK Biobank, which followed people for at least a decade. They found that people on the LCHF diet had higher levels of low-density lipoprotein and apolipoprotein B. Apolipoprotein B is a protein that coats LDL cholesterol proteins and can predict heart disease better than elevated levels of LDL cholesterol can. The researchers also noticed that the LCHF diet participants’ total fat intake was higher in saturated fat and had double the consumption of animal sources (33%) compared to those in the control group (16%). “After an average of 11.8 years of follow-up – and after adjustment for other risk factors for heart disease, such as diabetes, high blood pressure, obesity, and smoking – people on an LCHF diet had more than two times higher risk of having several major cardiovascular events, such as blockages in the arteries that needed to be opened with stenting procedures, heart attack, stroke, and peripheral arterial disease.” Their press release also cautioned that their study “can only show an association between the diet and an increased risk for major cardiac events, not a causal relationship,” because it was an observational study, but their findings are worth further investigation, “especially when approximately 1 in 5 Americans report being on a low-carb, keto-like or full keto diet.”

I have to say that I find these findings not in the slightest bit surprising and would fully expect the relationship to be causal. The current craze for this diet is concerning and we need to warn consumers that they might be doing themselves considerable harm.

Other authors have recently pointed out that, within the first 6-12 months of initiating the keto diet, transient decreases in blood pressure, triglycerides, and glycosylated hemoglobin, as well as increases in HDL and weight loss may be observed. However, the aforementioned effects are generally not seen after 12 months of therapy. Despite the diet’s favorable effect on HDL-C, the concomitant increases in LDL-C and very-low-density lipoproteins (VLDL) may lead to increased cardiovascular risks. And another team of researchers has warned that “given often-temporary improvements, unfavorable effects on dietary intake, and inadequate data demonstrating long-term safety, for most individuals, the risks of ketogenic diets may outweigh the benefits.”

33 Responses to Following the ‘keto diet’ could double your cardiovascular risk

  • I disagree but will admit that eating Keto is a bit radical for most people… even for me. I could manage the Keto diet if I really felt the need. However, my health is good enough without it…. at least for now. Maybe some here don’t know it, but many many people are eating a carnivore (only) diet, and are doing much better than they did before eating carnivore. In fact, most will testify to loosing extra weight, feeling great… and riding themselves of chronic diseases.

    Cholesterol in my view is not the culprit in heart disease. Rather, the problem is inflammation., inflammation from what ?…. many an MD will point the finger at sugar and carbs instead. The constant drumbeat slamming cholesterol has been going on for decades, with cholesterol targets lower and lower than in the ’70s. Yet, heart disease continues to be a growing problem eve n with most MD’s and patients targeting lower cholesterol. Yes, cholesterol is found at the scene of the crime, as is said here correlation but not causation. So it’s the view of many that cholesterol is wrongly blamed for being the actual murderer.
    Doctors witness dead patients with cholesterol of 150, and conversely patients with no issues that have cholesterol of 250. Patents that take statins complain to the doctors of no energy, “can’t get out of the chair doc”, at the same time complaining of heart pain.
    I knew a friend, some 25 years ago. He was a runner. In his forties he competed in 10K. He was not fat and in what appeared to be good health. He was doing fine until his doctor put him on statins (for high cholesterol), a few months later he passed before he reached his mid-forties. Statins have a negative effect on muscles, including the heart muscle.

    • “I disagree but” I HAVE NO EVIDENCE.
      “Cholesterol in my view is not the culprit in heart disease” BUT I HAVE NO EVIDENCE.
      “I knew a friend, some 25 years ago” BUT I HAVE NO EVIDENCE.

      • @EE

        SO if the problem was Cholesterol, and Statin medication was the solution, why didn’t he die before he was taking the medication instead of after ?
        Proof enough for me.

        To all my “friends” here. I read that patients on statins drugs feel like crap… but you tell me they’re great for the heart… ok.
        I’m supplying Statins to all my friends for Christmas this year. Give me your address and I’ll be sure to send you a large supply…. enjoy.

        • To all my “friends” here. I think that RG posts stuff that reads like crap.

        • @RG

          I have a friend who has been on statins for around a decade, he is in his early 40s now and healthy. He has a genetic condition where in his body produces too much Cholesterol and statins saved his life.

          My dad has been on statins since his heart surgery over a decade ago and his CV health has been so far good for his age.

          Proof enough for me that statins save lives.

          Therefore, send me all the statins that you can purchase using profits from you big pharma investments that you love so much:

          BTW I too have a lot of anecdotes I can share. We can co-author that sleepy-time children’s book I talked about earlier. There is money to be made at putting kids to bed and we can be rolling in a lot of dough by this time next year. Think about it.

          P.S: Trying you had at sarcasm, RG? I thought that was my job. I got competition now.

          • @Talker

            lol… again you refute my anecdote with your anecdotes as “proof”…. touché

            If you want a good explanation of what is happening when cholesterol is too high, this instructional video can explain what some (many) people don’t know about cholesterol. Perhaps even some MD’s.


          • lol… again you refute my anecdote with your anecdotes as “proof”…. touché

            Why RG? I can’t use a page from your own playbook? You have very strict double standards for a pro-death troll.

            I don’t know what point you are trying to make by arguing that high cholesterol is bad. I never took the position that cholesterol is good for anyone. Jeez…keep up with the conversation.

            Besides if MDs stop prescribing meds, your big pharma investments would go bankrupt. Keep biting the hand that feeds you. 🤣

    • RG,

      You don’t realize the power of your anecdotes. I read them to my kids and that put them to sleep very quickly. It even makes me sleepy, don’t need to take my sleep meds anymore, suck on that big pharma.

      May I have your permission to publish your anecdotes as a children’s bed-time story book?

    • Any chance of something to support the “inflammation” idea? It’s one I’ve come across a few times, but without much back up.

      Also “heart disease” is a very vague catch all: I have what might be termed a “heart disease”, but my cholesterol levels are fine and there is no evidence of inflammation either (MRI scan, angiogram, echo cardiogram).

  • It’s good policy to view any nutrition research skeptically. At the same time, when you’re talking about weight loss, you have to consider any potential risks in opposition to the risks of obesity (which are well known and solidly researched). If a person is unable to stick to a low-risk diet (calorie counting, heavily plant-based) then a higher risk diet that they can stick to may still impart less risk than staying obese.

    I’m one of those people and have kept off the 50 pounds I lost for over 5 years now. My CV risk is probably higher than it would have been if I went vegetarian or counted calories, but I’ve failed at sticking to those diets, so they aren’t true alternatives for me. That leaves me to balance keto risk vs obesity risk, and from the research I’ve done, keto risk seems lower. My BP & cholesterol numbers support that hypothesis.

    All that said, I suspect that what was effective for my N=1 experiment wouldn’t generalize to the population level. My first recommendation to anyone would still be to try calorie counting and eating more plants before trying keto, because keto is riskier, more expensive, and easier to mess up in ways that will actually make things worse. It also has less evidence for weight loss, regardless of how impressive it’s been for me personally.

    • @L

      Thanks for sharing your personal findings. I commend you for taking an active role in better hearth. Dieting is not easy until it becomes a way of life. Don’t worry, you don’t need to count calories or eat vegetarian, just keep watching the scale or your belt size, and you’ll know how you’re doing. Since you stated that your blood pressure is good, then I will assume your cholesterol is not going in the wrong direction. However, only a blood test can tell for since high cholesterol has few symptoms. Good cardiovascular health is tied to insulin resistance/sensitivity as much as anything … including cholesterol.
      I changed for the better after reading the book by Dr. Benjamin Bikman “Why We Get Sick”. I recommend it. But you can also find him on YouTube. I took his advice and eat within a sixteen-hour window every day. Some people are more extreme and only eat one time per day (and all in-between). The food we eat does matter, but not eating round the clock matters also (intermittent fasting). Lots of good changes in my health.
      Nuff said.

    • Thanks L for presenting a somewhat dissenting view without going full-on crank. Your anecdote is actually helpful, but without further details, you age for instance, it’s hard to draw any conclusions–which you don’t, beyond your personal experience–thus far. The results of the risk you are taking may not show up in five or ten years, but I must commend you for maintaining your weight loss. Please consider switching to something less risky.

      For the life of me, I don’t understand why people are so unwilling to count calories. It’s usually presented as something so very onerous. I’ve been doing it for 18 years now although it’s no longer a conscious thing. I’ve retrained my brain to accept smaller portions and I know what those portions are for me to maintain my weight. Sadly this does not include ice cream more than twice a year, but the upside is that a treat that really is a treat is enjoyed so very much

      • Re: counting calories: I think different things are hard for different people. Lots of people find keto hard, but I don’t. I do find being hungry all the time hard, though, which was my experience when counting calories (and eating at a very modest 300 calorie deficit). That was the main problem, but there’s also the hassle of tracking everything, not knowing how many calories are in foods cooked by others, and having to weigh things every time I cook (I cook a lot, which is part of why keto is easy for me).

        I would say that if it’s “no longer a conscious thing” you’re not really counting calories any more, just eating the right amount. Which is great! But I was never able to get to that point the couple of times I tried that method. If I could eat that way and have more carbs without feeling hungry all the time, I *absolutely* would – bread and pasta and potatoes are delicious!

        Re: my personal risk factors: I think this part of the linked article is relevant:

        “When asked if there were any groups that were not harmed by following a LCHF diet, Iatan said how long people are on the diet and whether or not they lose weight “can counterbalance any LDL elevation.”
        “there are various ways to put together a LCHF diet, and it is very unlikely they all have the same effects on serum lipids or cardiac events.”

        I’ve been on it a long time, my LDL is actually lower now than pre-keto, and the way I eat is probably more heart-friendly than most Americans, keto or not. I actually eat more vegetables now than I did before, at least 2 servings at most meals. Again, this is the problem with making generalizations around nutrition research. The less clearly you define the diet the less reliable your findings. Edzard took an article about “keto-like” diets (which aren’t actually keto-like at all because they’re missing the *one thing* – ketosis – that defines a keto) and used it to fear monger around a class of diets that may not actually be harmful at all (or may only be harmful if done in certain ways).

        • @L

          This link below speaks to the fact that people who see their cholesterol go higher after changing to a lower carb diet should not be dismayed. Just let your body do what it does, control cholesterol at the levels it needs. Continue monitoring your BP, relax and enjoy. This conversational interview with Dr. Nadir Ali & Dr. Eric Berg is a fantastic amount of information on cholesterol from this specific cardiologist. Patients are traveling great distances to see him … not for meds, but for advice on eating.

    • Oh also I wanted to point out that this study isn’t actually about keto diets, but “keto-like” diets. The study group included people eating up to 25% of their calories from carbs (which would be too much to remain in ketosis). Your headline is therefore misleading. This study wasn’t about “the keto diet.”

      This is a pretty common problem with keto diets (both in practice for dieters and from a research standpoint when relying on self reports) – they’re hard to follow and a lot of people who try them end up either doing it wrong or doing it stupidly. It’s easy to fall into a “worst of both worlds” state where you’ve just increased your fat intake without going into ketosis, or to eat too much fatty meat and not enough plants (which is what I was referring to in my comment above when I mentioned it was easier to mess up in ways that make things worse compared to more tried-and-true options).

      • @L

        You make an excellent point about the “keto-like” diet study. While 25% carb does not represent anything close to keto, it’s actually about half what the current authorities are recommending to the population for daily carb intake, that is significantly different. Dr. Benjamin Bikman does promote low carb eating, however, for those that want to begin by reducing insulin resistance and kicking the sugar addiction. He differentiates some bad carbs from others, as well as promotes IF (intermittent fasting). Bikman is not alone, there are many MD promoting the same thing. Dr. Sten Ekberg is many many good YouTube videos promoting health through eating.


    Results 6 studies for primary prevention and 5 for secondary prevention with a follow-up between 2.0 and 6.1 years were identified. Death was postponed between −5 and 19 days in primary prevention trials and between −10 and 27 days in secondary prevention trials. The median postponement of death for primary and secondary prevention trials were 3.2 and 4.1 days, respectively.

    Conclusions Statin treatment results in a surprisingly small average gain in overall survival within the trials’ running time. For patients whose life expectancy is limited or who have adverse effects of treatment, withholding statin therapy should be considered.

    Statins might have some benefit for those who have already had a cardiac event. But otherwise the results are pretty meager. If those people were taken out of the study, would the results be negative for statins? With all the side effects of statins, why bother unless you are in the at risk group?

    • You are talking tosh, stan. Statins are a marvelous invention that preemptively saves lives. One should take them as prescribed by a doctor. You need to experience the magic of statins firsthand. Otherwise, anything you say about statins is moot.

      • Cholesterol classes 101

        Why stopping at labeling cholesterol good/bad is insufficient, there is more to it than that.
        Cardiologist outlines the case against statins.

        • could you perhaps also find a video of a geologist outlining the case for a flat earth?

          • Cholesterol is not the CAUSE of heart disease. There is an association because inflammation already exists due to other reasons. C’mon professor, wake up. Higher cholesterol in patients does not automatically equal higher incidence of heart disease.
            Statistics in Japan proved otherwise, where use of statins is high.

          • I’m so glad I have you!
            What would I do without you?
            Finally, someone showed me the light.

      • Talker- without wishing to enter into a debate about the value or otherwise of statins, your point to Stan that ‘you need to experience the magic of statins firsthand. Otherwise, anything you say about statins is moot.’ cannot be correct. This and other similar blogs, as well as recorded human history have shown endlessly how personal experience on matters health and disease are fraught with the difficulties of establishing the truth or otherwise. Recorded scientific endeavours of others who may never personally have had to ingest statins should be the guide. Nothing new about that , I know!

        • have you heard of a thing called IRONY?

          • Talker- your quote about the need to experience statins first hand has no irony in it ; you meant it literally and you know it. It would and does make no sense if the opposite was your intended meaning. You’ve made a simple error and, as with another on this blog, haven’t the humility and good sense to concede it. If it was intended as irony then , in my opinion, it was an extremely and unsuccessful attempt.

          • Edzard- I fink so. They make them big bridges wiv it .

        • Leonard,

          I agree with you that you and I do not need to debate on the topic. That said, stan fully understands what I am talking about.

      • I newly came across this information from via NIH I was previously not familiar with about statins.
        So, it seemed a opportune place to post this information.

        The conclusion is that statins medication use (specific doses) for high cholesterol can lead to diabetes….. huh ? That’s a wow.
        So potentially trade a life-threatening disease for another disease that is known to be an accelerated death. Now the patient needs two medications instead of one to stay alive. How great is that ?

        Conclusion – “Statin treatment increased the risk of type 2 diabetes by 46%, attributable to decreases in insulin sensitivity and insulin secretion.”

        • Randomized trials suggest moderate-intensity statins increase type 2 diabetes risk by around 11% with a potential further 12% moving to high-intensity statins, such that high intensity may increase risk by 20% or more relative to placebo. These data translate into one extra diabetes case per 100-200 statin recipients over 5 years, with ∼10-fold greater benefits on major vascular outcomes. (

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